aboutsummaryrefslogtreecommitdiff
path: root/compiler-rt/lib/builtins/floatsidf.c
diff options
context:
space:
mode:
Diffstat (limited to 'compiler-rt/lib/builtins/floatsidf.c')
-rw-r--r--compiler-rt/lib/builtins/floatsidf.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/floatsidf.c b/compiler-rt/lib/builtins/floatsidf.c
new file mode 100644
index 000000000000..2c66167d794d
--- /dev/null
+++ b/compiler-rt/lib/builtins/floatsidf.c
@@ -0,0 +1,57 @@
+//===-- lib/floatsidf.c - integer -> double-precision conversion --*- C -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements integer to double-precision conversion for the
+// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
+// mode.
+//
+//===----------------------------------------------------------------------===//
+
+#define DOUBLE_PRECISION
+#include "fp_lib.h"
+
+#include "int_lib.h"
+
+COMPILER_RT_ABI fp_t __floatsidf(int a) {
+
+ const int aWidth = sizeof a * CHAR_BIT;
+
+ // Handle zero as a special case to protect clz
+ if (a == 0)
+ return fromRep(0);
+
+ // All other cases begin by extracting the sign and absolute value of a
+ rep_t sign = 0;
+ if (a < 0) {
+ sign = signBit;
+ a = -a;
+ }
+
+ // Exponent of (fp_t)a is the width of abs(a).
+ const int exponent = (aWidth - 1) - __builtin_clz(a);
+ rep_t result;
+
+ // Shift a into the significand field and clear the implicit bit. Extra
+ // cast to unsigned int is necessary to get the correct behavior for
+ // the input INT_MIN.
+ const int shift = significandBits - exponent;
+ result = (rep_t)(unsigned int)a << shift ^ implicitBit;
+
+ // Insert the exponent
+ result += (rep_t)(exponent + exponentBias) << significandBits;
+ // Insert the sign bit and return
+ return fromRep(result | sign);
+}
+
+#if defined(__ARM_EABI__)
+#if defined(COMPILER_RT_ARMHF_TARGET)
+AEABI_RTABI fp_t __aeabi_i2d(int a) { return __floatsidf(a); }
+#else
+COMPILER_RT_ALIAS(__floatsidf, __aeabi_i2d)
+#endif
+#endif